The present invention relates to an extreme pressure grease composition and, more particularly, to a grease composition containing a poly(alpha-olefin).
The need for high performance grease compositions capable of supplying good wear properties over a broad temperature range and under extreme pressures is well established. Such lubricants find their principal application in high speed aircraft and aerospace vehicles.
Christian, U.S. Pat. Nos. 3,642,626; 3,622,512; and 3,814,689 disclose grease formulated from polyol aliphatic esters, fluorinated polysiloxanes and polyol aliphatic ester/fluorinated polysiloxane blends. While these greases have been useful as extreme pressure anti-wear lubricants at temperatures ranging from -100.degree. F. to as high as 450.degree. F., their utility has been restricted due to their inability to prevent temperature increases. As a result, they are not well suited for use in transmission applications where the ability of a grease to dissipate heat and prevent heat generation is critical.
Heilman et al, U.S. Pat. No. 3,876,720 discloses a class of olefins (herein referred to as poly(alpha-olefins)) which are dimers of vinylidene compounds. Heilman states that these olefins are useful as engine lubricants, hydraulic fluids and grease bases useful under extreme pressure conditions. However, while Heilman recognizes this utility for the olefins, the patent does not disclose any grease compositions as such.
Thus, none of the prior art teachings, including Heilman and Christian, disclose a grease composition that has heat dissipation and heat prevention properties and is useful as a transmission grease over a broad temperature range and under extreme pressure conditions. Accordingly, the need remains for such a great composition.